Why Ireland would Benefit from a National Screening for Osteoporosis
Written by Professor John J. Carey, Consultant Physician, Galway University Hospitals. Email: john.j.carey@nuigalway.ie and Dr. David O’Sullivan, House Officer in Orthopedic Surgery, Galway University Hospitals.
Osteoporosis is the commonest skeletal disease worldwide. Failure to attain or loss of skeletal mass and quality result in weak bones leading to fractures. Osteoporotic fractures are one of the leading causes of morbidity and mortality in older European adults, and one fragility fractures (FF) one of the most expensive. 1-3 A recent European report notes Ireland has one of the highest rates of fracture but will experience the greatest increase in numbers over the coming decade. While Ireland performed well on certain domains, we did not on national policy, guidelines or investment. 4 If we are to address the rapidly increasing burden of this illness and the associated costs for patients, their social network and our country, fundamental shifts in knowledge, policy and how our healthcare system is run are needed. In 2008 the H.S.E. estimated the direct cost for caring for Irish people with FF will be ¤2billion, a doubling from 2020. 5 As things currently stand we do not have the resources to manage what is already happening. Providing poor quality care has limited benefit, increases costs and harm to patients. We need a rapid escalation in resources and policy to support quality osteoporosis services for so Irish people.
Osteoporosis can be diagnosed in the setting of a fragility fracture, particularly of the proximal femur or spine. 2, 6
These are the clinical events of this disease, the majority of which occur following a fall. Thus all patients should be assessed and considered for appropriate pharmacologic intervention and fall prevention, in addition to addressing any underlying causes or modifiable risk factors following these events. 2, 7 Unfortunately despite overwhelming evidence showing diagnosis and treatment are the most effective way to reduce subsequent fracture risk, 2, 6, 8 there is a considerable gap between the evidence and recommended management and what is actually taking place in practice. 8-10 For example data from the H.I.P.E. portal, the public hospital inpatient administration system shows fewer than 20% of those adults aged 50 years and older admitted with a major osteoporotic fracture over the past 15 years are diagnosed with osteoporosis. In Galway University Hospitals the treatment gap was similar, but following the establishment of a fracture liaison service this number increased to >80% for hip fracture patients between 2009 and 2018 (Proceedings from World Congress of Orthopedic Nurses 2018).
Recently a national steering committee was established to address these deficiencies. A recent audit reviewed international standards for fracture liaison services, and a brief overview of where things stand at present in Ireland. 8 This group are essential to garner support for resources, logistics and audit for these patients, which will require considerably greater support than currently exists in any public facility. Fracture liaison services are critical to bridging some of these gaps in care, and while effective, this is secondary prevention. 11 A more fundamental approach though is primary prevention delivered via evidence based, planned and resourced screening programmes. 12
What is Screening?
Screening is a process to identify asymptomatic people at increased risk of a disease before it occurs, so interventions can be implemented to reduce their chance of developing it, or the severity of illness when it occurs. Screening is not the same as early diagnosis. Effective screening programmes are an imperfect filtration process which can identify those at risk, while minimising the harms and costs associated with overdiagnosis and ineffective interventions. 12 Testing people with fractures is therefore not screening, rather diagnosing or monitoring. In 1968 the World Health Organisation (WHO) published 10 criteria which must be met in order for a screening programme to be effective. These are still valid today, as recently cited in 2020 by the WHO, 12 and are thus worth looking at from an Irish perspective, as outlined in Table 1. Unfortunately loose use of the terms ‘screening’ and ‘testing’ in the medical literature can lead to confusion, and some authors and papers use these terms interchangeably even for those with fractures.
The WHO have agreed and published a number of reports for screening postmenopausal women for osteoporosis, in particular Reports 843 in 1994, and 921 2003. These outline in extensive detail the epidemiology and natural history of osteoporosis, describe analogies to other disease areas such as cancer and cardiovascular disease, and propose standards for screening those deemed to be at risk. The 1994 report proposed what is still the accepted standard today, a T-score of <-2.5 as the diagnostic threshold for the diagnosis in postmenopausal women. These criteria have been modified and improved over the following 3 decades by the International Society for Clinical Densitometry (ISCD), such that further clarifications have been added, and they may also be used for men aged 50 years and older. These details are available through the ISCD website (https:// iscd.org/learn/official-positions/) which are an essential guide on who should be referred for DXA testing, how it should be done, how DXA testing should be reported and how to interpret the reports in clinical practice.
Today major international organisations agree screening postmenopausal women is appropriate, and both clinically and cost-effective.
The majority recommend screening all women aged 65 years and older, and younger women with major risk factors such as a family history of osteoporosis, corticosteroid use or rheumatoid arthritis. There is less consensus for men, in part due to some ambiguity around the interpretation of the epidemiology and treatment effectiveness in men. Most agree however that some screening is appropriate as men make up between 20% and 30% of all FF, but acknowledged the uncertainty around who exactly should be screened, and what interventions might be used. In the USA, UK and ISCD guidelines screening is recommended for men aged 70 – 75 years and older, and younger men with major risk factors, similar to postmenopausal women.
The United States Preventive Services Task Force (USPSTF) has undertaken a number of comprehensive and quantitative assessments of the effectiveness of screening, most notably in 2002 and 2018 . Using published data from 2002, we can see in figure 1 the importance of picking an appropriate age for screening. 13 If one were to screen all women aged 50 years and older (or men presumably), the number needed to screen to prevent 1 hip or 1 vertebral fracture would be almost 10 fold higher than starting screening at age 65-70 years! And the rate of overdiagnosis would be much greater in the younger agegroup. If 1 additional risk factor is added, such as body weight, then the number needed to screen can be reduced. This latter aspect is important as it enables best use of resources, and will reduce the cost and harm associated with a screening programme.
In the same year as the first USPSTF report was published, a group of researchers in Asia developed the Osteoporosis Self-Assessment Tool or OST for short.
This tool combines age and weight to help identify those most likely to have osteoporosis. By adding weight, multiple authors have shown the number needed to screen can be reduced by around 30%. 14, 15 Waiting times for public DXA in Ireland are long, years in some centres. Access to quality DXA is even longer. We have recently validated the OST for Irish men and women showing it works similarly well to other populations and could reduce the number of men and women referred for screening DXA. 16 Although many DXA facilities provide an excellent service, poor quality DXA services are endemic in Irish practice. New legislation, coupled with site inspections by H.I.Q.A. and standards and training programmes provided by the Irish DXA Society are addressing these shortcomings.
Fracture risk algorithms are also used but their goal is to assess the risk of fracture, not those with low BMD, which is arguably more important. Both FRAX ® (https:// www.sheffield.ac.uk/FRAX/tool. asp?country=48) and QFracture ® (https://qfracture.org/index.php) have been studied in large Irish populations. 9, 17 Both tools use similar data to estimate the 10 year risk of major osteoporotic fracture and hip fracture, and have important strengths and limitations. 9, 17, 18 The 10 year risk can thus be estimated via websites with or without BMD data. Because fracture risk is probabilistic and heuristic, these tools provide a reasonable and rational estimation. However, the performance of screening tools is less robust in younger populations 19 who are generally at considerably lower risk, which further emphasizes the importance of age in the criteria for establishing an effective strategy.
Thus it is clear today that for the first time in Ireland we now have the availability of the essential components required to devise and roll out a national screening strategy for osteoporosis, based on science, international standards and Irish data.
There are 3 essential steps for the process, whose exact deployment details have yet to be worked out, and where modifications will be needed over time.
- A Modified OST with Irish thresholds;
- DXA scan for those who are below the threshold;
- A Fracture Risk Estimation with or without the DXA test, which can be reviewed and repeated at appropriate intervals or if a patients circumstances change.
This process is probably best outlined in an example where we consider the OST, DXA and FRAX tools for 2 women who differ only in age as shown in Table 2. Those identified as being at high risk, above an agreed and appropriate threshold, could then benefit from appropriate evidence based interventions to reduce their risk of fracture, reduce the risk of unnecessary testing and treatment as exists today, provide a more accurate and efficient programme to reduce the burden of illness for patients and the cost of healthcare
In summary
Osteoporosis and the resulting fragility fracture is a national crisis which is deteriorating rapidly. We do not have the resources to manage the current illness burden, which is rising rapidly as people live longer, often with more complex needs. While secondary prevention works, and needs more work and resources too, a national screening strategy could be even more clinically and cost-effective by reducing this burden with evidence-based primary prevention. Support and policy for quality DXA services are required rather than just more DXA scanning. We have the tools, we have the data, but action is needed now.
References available on request
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